Based on our model of how mothers's perceptions of their efficacy in childcare may affect child-care performance and, in turn, infant development, we propose an experimental study of Down syndrome infants and their mothers. Our model posits the contribution of cognitive and affective processes in the development of effective versus ineffective child-care coping styles. It emphasizes the importance of a mother's perception of her control over child-care events. Our specific aims are: 1) to utilize simulated child-care tasks to determine effective versus ineffective coping strategies of mothers with Down syndrome children; 2) to determine the effect of parental perceptions, especially those varying in expectations for the infant, on subsequent parental behavior; 3) to determine the relation between physiologic response indices of attentional processing and behavioral patterns during mother- infant interaction and developmental outcome, and 4) to validate measures collected in the laboratory with behavior in an actual child- care task and with developmental outcome. In experiment I we will measure the developmental progress of children with Down syndrome by linking maternal measures to two developmental outcome measures--the Baylor index of developmental status and language competency of the Down syndrome child. In Experiment II we will explore the role of parental cognitive set (experimentally varied expectations) on the subsequent performance of mothers of typically developing children in a simulated child-care task. Results from these proposed studies will be of clinical significance in that the information gained can (1) provide a theoretical framework to guide clinicians in their interactions with DS families and (2) help determine the importance of cognitive processes as mediators of behavior change when intervention strategies are proposed for mothers with Down syndrome children.